Allan A Dale is an expert robber with a sarcastic and funny nature. Allan's traits can be used to avoid capture, get food to the poor, and make useful contacts. But—as we find out—if skills like that were to fall into the wrong hands, there would be big trouble. Allan first joined the gang when Robin saved him from hanging at the behest of the Sheriff of Nottingham. But after a year in the forest, when he felt they were just scraping by, Allan began to want more than this earnest existence could offer. The temptation of power and money led him astray. Eventually, he rediscovered his values and earned back the respect of the gang. At one point, he admits (at the same time as Will Scarlett, rather awkwardly) that he "likes" Djaq, the Saracen girl in the gang.Near the end of the first season, Allan and Will (at Allan's urging) briefly court the idea of taking their share of the loot and going to Scarborough to live with Will's family, but ultimately return to the gang in time to save Robin and the gang from getting killed, but not in time to save Marian from apparent death after being stabbed as the Night Watchman.

Not long after, after being captured and tortured by Gisborne, Allan begins selling him information. After Robin finds out that he has turned traitor, Allan goes to work for Gisborne as his "right-hand man". However, he doesn't sell out completely as he never gives away the location of their secret camp, nor does he give away Marian's alter identity as the Night Watchman, and he tries to help keep the lovelorn Gisborne away from Marian. Near the end of the second season, Allan returns to the band of outlaws and helps them fight for their lives against an army of mercenaries hired by the sheriff. After Lady Marian's death in the Holy Land, Allan returns to England with Little John, Much, and Robin and the crew is joined by Tuck and Kate. In the third season, after the Sheriff is killed, Gisborne's sister, Isabella, tricks Robin into thinking Allan has been helping her, thus betraying Robin yet again.No one believes him when he says he didn't betray the gang and Robin ties Allan up, but he escapes. The gang later find out he is innocent. After he escapes he sees a mysterious figure walking through the forest. Knowing he has to warn Robin, he begins to run as fast as he can, but receives three arrows in the back and The old Sheriff, who is not really dead, killed him and lays his body in front of the gates of Nottingham, which has been taken over by Robin. The gang of outlaws find him, and John carries the body into the castle as Sheriff Vaisey advances towards them. Much and John burn his body, with Much saying "To Allan, our loyal friend."

Allan seemed to be capable with a sword and was exceptionally agile. He was able to hold his own against Robin Hood on two occasions, but on the second he was both taken by surprise and, also, didn't want to fight his old comrade.

His skills were mainly in trickery and conning. He was an avid gambler and something of an addictive player of betting games.